The present invention relates to apparatus for casting molten metal for the production of metal castings by so-called xe2x80x9clost-foamxe2x80x9d technology.
In particular, the invention relates to apparatus of the type comprising:
a first container of molten metal,
a second container having an upper mouth and containing a bath of granular material, immersed in which is a pattern made of expanded material which can evaporate when contacted by the molten metal, and
filling means for supplying the molten metal from the first container to the pattern in the second container.
The primary object of the invention is to provide apparatus which enables the liquid metal to be transferred from the molten-metal container to the pattern without time limitations and without limitations of the amount of metal required to fill the pattern or form.
For this purpose, a subject of the invention is apparatus of the type mentioned above which is characterized in that it comprises:
means for applying a partial vacuum to the second container, the means comprising a removable cover which can seal the mouth of the second container in a leaktight manner and which has a first opening with which vacuum-generating means ere associated and a second opening with which the filling means are associated in a leaktight manner so that, when the cover is fitted on the second container in a leaktight manner and the vacuum-generating means are activated, the liquid metal is transferred from the first container to the pattern.
A second subject of the invention is a method of casting under reduced pressure, which uses the above-mentioned apparatus.
Further advantages and characteristics of the apparatus and of the method according to the invention will become clear from the following detailed description, given with reference to the appended drawings, in which: